Hi Mel, whilst i have mucking around trying to get Methylcobalamin, i ran out of my normal b12 Cynnocobalamin about 10 days approx without it, but still took my b complex but anyway 3 days ago i noticed a real slump in my energy so i went and got some more b12, well it give me a boost on the same day i took it, and have remained the same since, i have been climbing up and down a high ladder painting the outside of my house, what a difference the b12 has made.
all the best
Brian